This invention relates to an electronic musical instrument generally called a music synthesizer which produces a musical tone in accordance with voltage corresponding to a note of a depressed key and, more particularly, to an electronic musical instrument of this type capable of producing a plurality of tones simultaneously.
The prior art music synthesizer can produce a desired musical tone by freely and subtly controlling the pitch, tone color and volume of the musical tone by means of a control voltage. The prior art music synthesizer, however, is disadvantageous in that it cannot produce a plurality of tones simultaneously.
This is because a note voltage generation circuit which produces note voltages corresponding to respective keys is incorporated in a keyboard circuit so as to produce a note voltage directly in response to actuation of a key switch. If the simultaneous reproduction of a plurality of tones is to be achieved in the prior art music synthesizer, a musical tone reproduction system including a voltage-controlled oscillator (VCO), voltage-controlled filter (VCF) and a voltage-controlled amplifier (VCA) needs to be provided for each key, which is quite unfeasible from standpoints of costs, size and utility.